Load binder

ABSTRACT

A variable advantage force applying device is disclosed as applied to a load binder used to tighten a flexible fastener such as a rope, cable or chain around a load to hold the load against shifting on the bed of a carrier or to fasten a bundle of heavy objects together. The device uses a lever pivoted to one end of the flexible fastener and connected to the other end of the fastener by a pin and slot. The slot is curved and disposed to move the pin toward the pivot for the lever as the lever is swung in a tightening direction. As the pin moves closer to the pivot, it increases the mechanical advantage of the lever at the stage of the tightening operation during which the resistance to tightening increases. An overcenter arrangement is incorporated in the pin and slot according to accepted design practice to hold the fastener in a tightened condition.

United States Patent [191 Rymsza [451 Apr. 10, 1973 LOAD BINDER [73]Assignee: MacLean-Fogg Lock Nut Co., Mundelein, Ill.

[22] Filed: June 10, 1971 [21] Appl.No.: 151,732

2,422,001 6/ l 947 Durbin ..254/78 Primary Examiner--Othell M. SimpsonAssistant Examiner-Robert C. Watson Attomey-Davis, Lucas, Brewer &Brugman [57] ABSTRACT A variable advantage force applying device isdisclosed as applied to a load binder used to tighten a flexiblefastener such as a rope, cable or chain around a load to hold the loadagainst shifting on the bed of a carrier or to fasten a bundle of heavyobjects together. The device uses a lever pivoted to one end of theflexible fastener and connected to the other end of the fastener by apin and slot. The slot is curved and disposed to move the pin toward thepivot for the lever as the lever is swung in a tightening direction. Asthe pin moves closer to the pivot, it increases the mechanical advantageof the lever at the stage of the tightening operation during which theresistance to tightening increases. An overcenter arrangement isincorporated in the pin and slot according to accepted design practiceto hold the fastener in a tightened condition. I I

6 Claims, 7 Drawing Figures LOAD BINDER This invention relates totightening devices for flexible fasteners such as ropes, cables, chainsor the like and will be described for illustrative purposes as appliedto load binders used to tighten a flexible fastener about a load on acarrier to keep the load from shifting.

Load binders as presently commercially available comprise a leverprovided with two pivots at one end, one pivot being connected to oneend of the flexible fastener and the other pivot being connected to theother end of the fastener or to an anchor on the carrier. The two pivotsare so related that as the load is tightened they pass one another andthen pass over the line of thrust, i.e., over center to lock in thetightened position.

The load binders are tightened manually, and, obviously, the effortrequired to bring them to the locked, over-center position increases asthat position is approached. To reduce the physical exertion required,the operator may increase the mechanical advantage of the lever byproviding a makeshift extension of the lever in the form of a pipeslipped over the end of the lever and extending beyond the lever tolengthen it. This renders the operator somewhat insensitive to themaximum allowable load for the binder, to the detriment of the binder,of the load being made secure and of the rope, chain or cable used asthe fastening means.

It is a broad object of this invention to provide a load binder whichreduces the maximum exertion required of its operator at the end-pointof the load binding operation as compared with the maximum exertionrequired by presently commercially available load binders.

A more specific object of this invention is the provision of a loadbinder which incorporates a variable mechanical advantage device as oneof the the connections between the binder and the flexible fasteningmeans, the device being arranged to increase the mechanical advantage ofthe manually operated lever of the binder as the binder approaches itsmaximum tightness, thereby reducing the effort put forth at that pointover the effort previously required.

As a still more specific object, this invention has within its purviewthe provision of a simple and inexpensive pin-and-slot form ofconnection between the lever of a load binder and the fastening means tobe tightened by it, said connection being so disposed as to function asa device for varying the mechanical advantage of the lever as the bindertightens the fastening means.

These and other objects of the invention will become apparent from thefollowing detailed description of a preferred embodiment thereof whentaken together with the accompanying drawings in which:

FIG. 1 is a plan view of the load binder of this invention shown in itsextended or unloaded condition;

FIG. 2 is a rear elevational view of a portion of the load binder ofFIG. 1 looking in the direction of the line 2-2 of FIG. 1;

FIG. 3 is a front elevational view of the load binder of FIG. 1; and

FIGS. 4, 5, 6 and 7 are fragmentary plan views of the mechanicaladvantage changing device forming part of the invention, the devicebeing shown in various stages of operation.

The load binder of this invention differs from prior load binders inthat one of the connections between the manually operated lever and theflexible fastener passing around the load is a pin-and-slot connectionrather than a fixed pivot, the slot being curved so that as the lever isturned about its fixed pivot the pin moves in the slot inwardly towardthe fixed pivot, thereby changing the effective moment arm to shorten itand thus create a progressively greater mechanical advantage for thelever which reaches a maximum just as the load binder passes dead centerinto a locking position.

Referring now to the drawings for a detailed description of theinvention depicted therein, the binder as shown in FIG. 1 is comprisedof a lever 10 having an end 11 which functions as a handle to be graspedby the operator, and having a fixed pivot 12 near its other end. A link13 is connected to pivot 12 for free movement therearound, said link 13being connected by a flexible connection such as another link 14 to ahook 15 adapted to engage one end 16 of a flexible tie element orfastener 17 such as a chain, cable or rope passing around a load (notshown). The other end of flexible fastener 17 is shown at 18 engaging ahook 19 which may be similar to or identical with hook 15. The generalobjective of the load binder is to draw hooks 15 and 19 toward oneanother to tighten the fastener 17 around the load. Alternatively links16 and 18 may be portions of separate fastening means the other ends ofwhich are connected to anchors on the bed or wall of a carrier such asatruck, plane or freight car.

The means by which the hooks 15 and 19 are drawn toward one anothercomprise a flexible connection 20 similar to flexible connection 14,said connection 20 connecting hook 19 to a link 21, the free end ofwhich is provided with a pin 22 appropriately retained within a curvedslot 23 formed in that end of lever 10 which extends beyond fixed pivot12. As shown more clearly in FIGS. 2 and 3, link 13 may be a cleviswhich straddles lever 10. Link 21 is in the form of a tongue whichpasses into a longitudinal groove 24 formed in the end of lever 10 andintersecting slot 23, said slot 23 extending on both sides of groove 24and providing spaced bearing surfaces for pin 22.

It may be noted that slot 23 is curved and extends in a general radialdirection with respect to fixed pivot 12. The line of thrust betweenhooks l5 and 19 passes through a plane which is perpendicular to theplane of FIG. 3 and is symmetrically disposed with respect to the sidesof clevis l3 and tongue 21.

To tighten fastener 17 around a load, handle 11 is swung clockwise asshown in FIGS. 4-7 about pivot 12 through somewhat less than from aposition in which lever 10 abuts the top of the clevis 13 to a positionwherein lever 10 is substantially parallel to and below tongue 21. Thetightened position is shown in FIG. 7 and the intermediate stages areshown in FIGS. 4, 5 and 6. It may be noted in FIG. 4 that the effectivemoment arm for the binder is the longest when the elements of the binderbear the relation to one another depicted in that FIG. The moment arm isshown by the arrow 26. When the moment arm is the longest, themechanical advantage of course is the least. It may be noted further inFIG. 4 that lever 10 has been swung through approximately 45 from therelaxed position shown in FIG. 1 and because of the curvature of slot23, pin 22 has slid a short distance from its end position.

In FIG. 5, lever 10 has been swung approximately another 5 to degreesand again, due to the curvature of slot 23, pin 22 has slidapproximately through the mid point in slot 23. This has still furthershortened the effective moment arm as shown by the arrow 27.

In FIG. 6, the lever 10 has been rotated approximately 80 from itsinitial position, which brings pin 22 to the inner end of slot 23. Atthis point the moment arm is the shortest and is shown at 28.

In FIG. 7 lever 10 has been swung as far as it is possible in aclockwise direction, and in the process, the line of thrust betweenhooks and 19 has passed through fixed pivot 12 and the binder now is inan over-center position which locks lever 10 in its left-hand positionas shown in FIG. 7.

.Thus with the variable mechanical advantage device of this invention,that is, the pin-and-slot connection between lever 10 and link 21, theforce required to be exerted by the operator on lever 10 is reduced asthe fastener is tightened as compared with the force that would berequired were a fixed pivot used in place of the pin-an'd-slotconnection as is commonly done in the prior art load binders. Thisdecreased force makes the load binder easier to operate and hencereduces or eliminates entirely the need for the use of extensions onhandle 11 such as the types previously resorted to by load binderoperators. The pin-and-slot connection is relatively inexpensive tomake, it is sturdy and requires no additional or new procedure for theoperation of the binder. v

. The curved slot provides stability to the binder as the lever 10 isswung for either tightening or loosening the binding force. Pin 22always seeks the position in the slot at which a tangent to the concavecurvature of the surface of the slot is at right angles to the line ofthrust through the pin. The movement of pin 22 is automatic in responseto the change in the location of the line of thrust.

Other forms of connections may be used in place of the pin-and-slotconnection illustrated herein. For example, a roller or slide may beused in place of pin 22 and slot 23 may be replaced by a concave camsurface. It is understood therefore that the foregoing description ismerely illustrative of a preferred embodiment of this invention and thatthe scope of the invention is not to be limited thereto but is to bedetermined by the appended claims.

I claim:

l. A load binder of the type adapted to develop and exert tensile forcebetween opposed first and second flexible tie elements and comprising,in combination, a lever having long and short arm portions extendingaway from opposed sides of a first pivot element which serves as afulcrum for swinging movements of the lever, the long arm portion of thelever serving as a handle through which operating force is appliedthereto, said short arm portion having a curved cam slot therein whichextends in a direction which is generally radial to the first pivotelement and has a concave cam surface provided by a longitudinal sidewall of the cam slot, saidfirst flexible tie element being connected tosaid first pivot element, a second pivot element mounted in said camslot and movable therealong from end to end thereof while engaged withsaid concave cam surface, said second flexible tie element beingconnected to said second pivot element and extending therefrom in adirection to urge said second pivot element toward said concave camsurface, said lever having a normal loose tie position in which the longarm portion thereof extends along one flexible tie element and atightened tie position in which the long arm portion thereof extendsalong the other flexible tie element, said pivot elements being movabletoward and from one another in stable increments which are dependentupon the position of said lever during swinging movements thereof aboutsaid first pivot to provide gradual changes of mechanical advantage asthe lever moves between said loose and tightened tie positions, thecurvature and disposition of the cam slot being such that a majorportion of said cam slot crosses the line of thrust between the tieelements and thereby causes the line of thrust to intersect said firstpivotelement during the swinging movement of the lever to and from thetightened tie position, and means for limiting movement of said leverafter said major portion of the cam slot has crossed the line of thrustin moving toward the tightened tie position of the lever.

2. A load binder as defined in claim 1, and wherein said concave camsurface is arcuate.

3. A load binder as defined in claim 1, and wherein said second pivotelement moves toward the first pivot element during an intermediateportion of swinging movement of the lever between the loose tie positionand the tightened tie position to provide a gradual increase of themechanical advantage of the lever during said intermediate portion ofthe swinging movement thereof.

4. A load binder mechanism of the type adapted to develop and exerttensile force along a line of thrust extending between two tie elementsand comprising, in combination, a unitary lever having long and shortarm portions on opposed sides of a fixed pivot element which serves as afulcrum for swinging movement of said lever by which the operation ofthe mechanism is effected, said long arm portion of the lever serving asa handle for applying force thereto, said short arm portion having acurved cam slot therein, one end of which curved cam slot is near saidfixed pivot element, and which cam slot extends away from the fixedpivot element and has a second pivot element mounted therein formovements along the cam slot toward and from the fixed pivot element asthe lever is swung around the fixed pivot element, one of said tieelements being connected to the fixed pivot element and extendingtherefrom in one direction of thrust, the other of said tie elementsbeing connected to the movable second pivot element and extending in adirection of thrust opposed to that aforementioned, said curved cam slothaving a concavely curved cam surface against which the movable secondpivot element is held in contact by the thrust applied thereto duringswinging movements of said lever, said lever having loose and tightenedpositions in which the handle extends in generally opposite directionsfrom the fixed pivot element, and the curvature of said cam surfacebeing sufficient to restrain the movements of the movable second pivotelement along the cam surface in relation to the angular swinging pivotelement.

6. A load binder mechanism as defined in claim 4, and wherein themovable second pivot element crosses the line of thrust extendingbetween the two tie elements at a position of said lever close to thesaid tightened position thereof.

1. A load binder of the type adapted to develop and exert tensile forcebetween opposed first and second flexible tie elements and comprising,in combination, a lever having long and short arm portions extendingaway from opposed sides of a first pivot element which serves as afulcrum for swinging movements of the lever, the long arm portion of thelever serving as a handle through which operating force is appliedthereto, said short arm portion having a curved cam slot therein whichextends in a direction which is generally radial to the first pivotelement and has a concave cam surface provided by a longitudinal sidewall of the cam slot, said first flexible tie element being connected tosaid first pivot element, a second pivot element mounted in said camslot and movable therealong from end to end thereof while engaged withsaid concave cam surface, said second flexible tie element beingconnected to said second pivot element and extending therefrom in adirection to urge said second pivot element toward said concave camsurface, said lever having a normal loose tie position in which the longarm portion thereof extends along one flexible tie element and atightened tie position in which the long arm portion thereof extendsalong the other flexible tie element, said pivot elements being movabletoward and from one another in stable increments which are dependentupon the position of said lever during swinging movements thereof aboutsaid first pivot to provide gradual changEs of mechanical advantage asthe lever moves between said loose and tightened tie positions, thecurvature and disposition of the cam slot being such that a majorportion of said cam slot crosses the line of thrust between the tieelements and thereby causes the line of thrust to intersect said firstpivot element during the swinging movement of the lever to and from thetightened tie position, and means for limiting movement of said leverafter said major portion of the cam slot has crossed the line of thrustin moving toward the tightened tie position of the lever.
 2. A loadbinder as defined in claim 1, and wherein said concave cam surface isarcuate.
 3. A load binder as defined in claim 1, and wherein said secondpivot element moves toward the first pivot element during anintermediate portion of swinging movement of the lever between the loosetie position and the tightened tie position to provide a gradualincrease of the mechanical advantage of the lever during saidintermediate portion of the swinging movement thereof.
 4. A load bindermechanism of the type adapted to develop and exert tensile force along aline of thrust extending between two tie elements and comprising, incombination, a unitary lever having long and short arm portions onopposed sides of a fixed pivot element which serves as a fulcrum forswinging movement of said lever by which the operation of the mechanismis effected, said long arm portion of the lever serving as a handle forapplying force thereto, said short arm portion having a curved cam slottherein, one end of which curved cam slot is near said fixed pivotelement, and which cam slot extends away from the fixed pivot elementand has a second pivot element mounted therein for movements along thecam slot toward and from the fixed pivot element as the lever is swungaround the fixed pivot element, one of said tie elements being connectedto the fixed pivot element and extending therefrom in one direction ofthrust, the other of said tie elements being connected to the movablesecond pivot element and extending in a direction of thrust opposed tothat aforementioned, said curved cam slot having a concavely curved camsurface against which the movable second pivot element is held incontact by the thrust applied thereto during swinging movements of saidlever, said lever having loose and tightened positions in which thehandle extends in generally opposite directions from the fixed pivotelement, and the curvature of said cam surface being sufficient torestrain the movements of the movable second pivot element along the camsurface in relation to the angular swinging movement of the lever duringthe mid-regions of the movements of the the lever between said loose andtightened positions.
 5. A load binder mechanism as defined in claim 4,and wherein said concavely curved cam surface is arcuate and hastangents which progressively become normal to the direction of thrust onthe movable second pivot element.
 6. A load binder mechanism as definedin claim 4, and wherein the movable second pivot element crosses theline of thrust extending between the two tie elements at a position ofsaid lever close to the said tightened position thereof.